| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for highly-accurately determining a posture of a spherical body to be driven by a piezoelectric element in a wide drive range. <P>SOLUTION: The method for determining a posture of a spherical body to be driven is configured as follows. A sensor is installed oppositely to an observation point on the surface of a spherical body 100. A vector amount in a sensor observation-face coordinate system is calculated from a sensor signal equivalent to a two-dimensional parallel-shift amount of the surface of the spherical body 100. The vector amount is converted into a reference coordinate system. A vector passing the center O of the spherical body is calculated by outer-product calculation so as to specify a rotary-shaft vector 181 by calculation. A radius r2 of a rotating face 182 orthogonal to the rotary-shaft vector 181 and including a sensor observation point 182 is calculated from a length ratio of a right triangle composed by a radius r of the spherical body 100 and a distance h between the center O of the spherical body and the rotating face. A rotation angle Φ is calculated from a vector length in the sensor observation-face coordinate system being equivalent to the radius r2 of the rotating face and a circular arc of the rotating face, thereby determining the posture of the spherical body 100. <P>COPYRIGHT: (C)2009,JPO&INPIT |
